Advice on going to a heavy arrow set up

[hunt_or_bust]

I've been shooting Kinetic XTs with a 100 grain head, HIT inserts. I wanting to try out some heavier set ups since I seem to always hear great things about it.

I'm wanting to try a 175 grain VPA head with the new GT Kinetic Kaos arrows. I'll be using their new ballistic collar as well. I'm not sure on the weights of the collar and whatever else it requires. I'm just wondering what shaft I should use, 200 or 300 spine? I understand the 200 spine would probably be better in the respect that with a fall away rest being overspined is ok, but I believe the heavier 200 spine arrow will have a lower FOC than the 300 spine arrow. If the 300 spine arrow is too weak I guess that makes my decision easier.

I have a 27 inch draw and cut my arrows for a shaft only length of 26.5 inches.

Anyone shoot an arrow set up similar to this? What spine are you using?

I'm thinking the 300 spine would be just about right with that short of an arrow but my knowledge on some of this is limited.

Thanks in advance

 

[5MilesBack]

I would think you could easily use the 300's at that length and draw. I've shot my 300's with a 210gr Silverflame up front on a 30" arrow and 32 1/2" draw without any issues out to 60 yards. I also have some of the 200's as well.

Haven't heard of the Kaos arrows before now.

 

[hunt_or_bust]

I would think you could easily use the 300's at that length and draw. I've shot my 300's with a 210gr Silverflame up front on a 30" arrow and 32 1/2" draw without any issues out to 60 yards. I also have some of the 200's as well.

Haven't heard of the Kaos arrows before now.

Kaos are the new kinetics, they phased out the XTs and pros.

 

[5MilesBack]

Kaos are the new kinetics, they phased out the XTs and pros.

What did they change on them? I was bummed when I couldn't find anymore Pro's. I try to stick with the .001" or straighter at my arrow length.

Where did you hear about the Kaos? Checked their website and there's nothing on there about new arrows.

 

[El Gavilan]

What is the draw weight of your bow and which bow it it?

Mike

 

[hunt_or_bust]

What did they change on them? I was bummed when I couldn't find anymore Pro's. I try to stick with the .001" or straighter at my arrow length.

Where did you hear about the Kaos? Checked their website and there's nothing on there about new arrows.

The kaos is .0025 straightness and the regular kinetic is like .006 straightness. I was bummed too, they are completely out of pros too. I was hoping to order a few dozen and stock up but none to buy. I have a buddy who works for a dealer and he told me the other day.

 

[hunt_or_bust]

What is the draw weight of your bow and which bow it it?

Mike

71 lbs, 2013 elite hunter

 

[El Gavilan]

I ran the numbers on TAP and the 300 will be a little light with the 175 gr. head but not to bad, the 200 would require a 28.5" arrow and 225 grain head to get it close. Using the 26.5 arrow and 175 head it wasn't even on the chart.

Mike

 

[hunt_or_bust]

I ran the numbers on TAP and the 300 will be a little light with the 175 gr. head but not to bad, the 200 would require a 28.5" arrow and 225 grain head to get it close. Using the 26.5 arrow and 175 head it wasn't even on the chart.

Mike

I have a half an inch to give for that arrow. If I got to a 26 inch arrow does that help?

Also I use a heavy nock (lighted) and a wrap so that might help a little too...not much I'm sure but....

Am I better off going with a 150 gr maybe?

I figured out that the ballistic collar will be 12.8 grains and the accutough insert is 24.6 gr. Maybe going with a 150 with that much weight in components will be better

 

[El Gavilan]

The 300 at 26" with a 125 gr broadhead, 10 gr wrap, 24 gr insert, 3 fletch at 6 gr each will be right on and .001 from perfect spine. If you leave it at 26.5 it comes in very close to right on as well, just a little tiny bit weaker. It is showing 465 gr. arrow with an 11.66 FOC. This program is usually pretty conservative and you can go weaker with good success so a 150 gr head would probably work just fine.

Mike

 

[hunt_or_bust]

I ran my setup on a software called OT2 and it said I would be a little on the stiff side with my components and a 300 spine with 175 gr broadhead

 

[jmez]

Can you just get a couple different arrows and see how they shoot? I wouldn't put much stock in any of the calculators.

 

[hunt_or_bust]

Can you just get a couple different arrows and see how they shoot? I wouldn't put much stock in any of the calculators.

I agree, but its interesting to run the numbers and see.
Unfortunately I'd have to order these arrows by the half dozen at the minimum, the only place I know that sells individual shafts does not have the 300s or the 200s.

 

[jmez]

Did you check Lancaster? Sometimes they will sell by the shaft.

 

[hunt_or_bust]

Yeah that's the place I was referring too.

 

[larryschwartz]

hunt_or_bust,

A few things about spine that you may or may not know, but it should help you understand the physics of your choices...

Spine is a reflection of how flexible the arrow shaft is. It is measured by setting an arrow shaft on two fixed points, placing a weight in the middle and seeing how far it flexes. A 300 arrow will flex .300 of an inch, the stiffer spined 200 arrow will only flex .200 of an inch. Now you know where the numbers come from.

An arrow bends (the archers paradox) when you shoot it because at the moment of release inertia keeps the front end in place for an instant while the back end is being pushed forward by the string. For the same arrow, the heavier the bows draw weight the more the arrow will flex. This is why it flexes/bends and this is why spine, or stiffness/flexibility, is important when selecting an arrow shaft.

Putting more weight up front will keep the front end there longer and makes the shaft relatively weaker or less stiff. This relative differnce is often referred to as dynamic spine because the spine of the actual shaft hasn't changed but the way you are using it (wiht a heavier point) makes it act like the spine has changed. So, you can use a stiffer shaft with a heavier point and get the same flight as an arrow with a lighter point and less stiff shaft. You can weaken a too stiff shaft with a heavier point if you need to and strengthen a too flexible shaft by using a lighter weight point.

Putting more weight at the back end, like using a heavier lighted nock or bigger feathers or a wrap or cresting paint, will give it a relatively weaker spine. So, you lighted nock may be making your shaft act a little weaker than you thought it might, although with most shafts it takes more than a few grains to make a difference. Also, using a longer length shaft will make the dynamic spine less stiff. If you are not paranoid about shooting the shortest arrow you can you could easily extend your length by an inch or so without andy problems. This will give you more mass and weight and let you up a size which will also give you more mass and weight.

More weight is a good thing. It allows your arrow to absorb more of the energy stored in your bow when you shoot it. This gives you two things. First more energy is stored so more remains in the arrow when it gets to its destination and it will penetrate more. Second, since more energy is transferred to the arrow there is less left over to remain in the form of noise, vibration, and hand shock. So, a heavier arrow will shoot quieter, hit harder, and penetrate deeper. All good things.

If I was going to work on more FOC on my arrows I would start with getting some heavier field points and try them on my existing arrows to see if it get better flight and penetration. If the spine is off then you can shorten the shaft (do your experimenting with just one or two shafts so you can play with it if you need to. If you need a stiffer arrow because you don't want to cut your shaft you might want to see if a friend or a pro shop has one that you could borrow or experiment with at the shop's indoor range. No need to change point weight AND shaft type. Too many variables to monitor to figure out why something is happening. Change one thing at a time.

I hope this helped and didn't confuse,

Larry Schwartz

 

[hunt_or_bust]

I'm gonna try and get my hands on some 300 spines, cut them to 27 inches and throw some 175 gr point on with a HIT insert and the new ballistic collar.

 

[5MilesBack]

I ran my setup on a software called OT2 and it said I would be a little on the stiff side with my components and a 300 spine with 175 gr broadhead

That's funny, because every time I see someone run some numbers on OT2, it almost always says the setup is too weak. Even if it shoots just fine.

 

[hunt_or_bust]

Just an update, Lancaster has the arrows in stalk so I ordered 1 of each spine, 200 and 300. Going to throw a 50 grain brass HIT insert in them and shoot them with a 200 grain point and see which flies and tunes the best. I'm thinking the 200 spine may need a 75 gr HIT insert to keep an FOC as high as I would like with a 637 gr arrow. Hoping the 300 spine with an overall weight of 580 grs and an FOC of about 19% will shoot well and not be underspined.